Minimum Capability Requirements for DirectX 8.0 Drivers
In addition to returning the D3DCAPS8 data structure in response to a GetDriverInfo2 query, the DirectX 8.0 runtime has other requirements that a driver must meet to be considered a DirectX 8.0 level driver.
A DirectX 8.0 driver must explicitly:
Report support for one or more vertex streams in the MaxStreams field of D3DCAPS8.
Report a maximum point sprite size of at least one in the MaxPointSize field of D3DCAPS8.
Modify its list of supported texture formats to support new style pixel format specifications.
Handle the new D3dDrawPrimitives2 (DP2) drawing tokens.
Handle D3dCreateSurfaceEx for vertex and index buffers even if your driver does not support video memory vertex buffer creation. Handles for system memory vertex and index buffers are passed to the driver.
Set the new posttransformed clipping flag D3DPMISCCAPS_CLIPTLVERT if the hardware supports clipping of posttransformed vertex data.
It should be noted that a driver is not required to support any of the new features of DirectX 8.0 such as pixel or vertex shaders, volume textures, point sprites (beyond the nonzero maximum point size), multisampling or even multiple vertex streams (as the driver can set the maximum number of simultaneous vertex streams to one) in order to be considered a DirectX 8.0 driver.